Multiple PIP2 binding sites in Kir2.1 inwardly rectifying potassium channels

FEBS Letters

Soom, Malle³  Kirsch, Cornelia²  Klinger, Reinhard²  Heinemann, Stefan H.³  Kubo, Yoshihiro¹  Schönherr, Roland³ 

[1] Department of Physiology, Tokyo Medical and Dental University, Graduate School and Faculty of Medicine, Yushima 1-5-45, Bunkyo-ku, Tokyo, Japan;Institute for Biochemistry, Medical Faculty of the Friedrich Schiller University Jena, Nonnenplan 2, D-07743 Jena, Germany;Molecular and Cellular Biophysics, Medical Faculty of the Friedrich Schiller University Jena, Drackendorfer Straße 1, D-07747 Jena, Germany

关键词: Inward rectifier potassium channel;    Voltage clamp;    Kir2.1;    Lipid–protein interaction;    Binding assay;    Phosphatidylinositol-4;    5-bisphosphate;    PIP2;    phosphatidylinositol-4;    5-bisphosphate;    PC;    phosphatidylcholine;    Rh-PE;    rhodamine-phosphatidylethanolamine;    PI3Kγ;    phosphatidylinositide 3-kinase γ;    GST;    glutathione S-transferase;   

DOI  :  10.1016/S0014-5793(01)02136-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Inwardly rectifying potassium channels require binding of phosphatidylinositol-4,5-bisphosphate (PIP₂) for channel activity. Three independent sites (aa 175–206, aa 207–246, aa 324–365) were located in the C-terminal domain of Kir2.1 channels by assaying the binding of overlapping fragments to PIP₂ containing liposomes. Mutations in the first site, which abolished channel activity, reduced PIP₂ binding of this fragment but not of the complete C-terminus. Point mutations in the third site also reduced both, channel activity and PIP₂ binding of this segment. The relevance of the third PIP₂ binding site provides a basis for the understanding of constitutively active Kir2 channels.

【 授权许可】

Unknown